<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    *{
      margin: 0;padding: 0;
    }
    ul li{
      list-style: none;
      width: 200px;
      height: 100px;
      float: left;
    }
    li:nth-child(1) {
      background: #da8383;
    }
    li:nth-child(2) {
      background: #e1e941;
    }
    li:nth-child(3) {
      background: #6ceb50;
    }
    .text{
      width: 100px;
      height: 150px;
      background: #2d3bda;
      /* clear: both; */
    }

    /* .clear{
      clear: both;
    } */

    /* .clear::after{
      content: '';
      clear: both;
      display: block;
    } */

    ul{
      display: flex;
    }
  </style>
</head>
<body>
  <div class="container">
    <ul>
      <li>1</li>
      <li>2</li>
      <li>3</li>
    </ul>

    <div class="text">Hello World</div>

  </div>
</body>
</html>